1. Field of the Invention
The invention relates to a verification server used as a means for the authentication of application users, and in particular for the authentication of users on a network.
2. Description of the Prior Art
In banking and other service industries, establishing the identities of clients, in other words, authentication, is an extremely important problem. Proper authentication is required in order to protect against any attempts by an impostor to withdraw or deposit money from another person's account.
The standard means of authentication is to ask to see some form of identification card, such as a driver's license. However, with the proliferation of automatic teller machines and other automatic devices in recent years, different means of authentication using magnetic cards and passwords have come into widespread use.
Some means of authentication is also necessary in fields other than banking. For example, at research institutions, in order to prevent secrets from being leaked, often only those with the proper clearance are permitted to enter certain restricted areas. Private membership clubs also often require some means of identification and authentication to prove membership. At these research institutions and clubs, the use of magnetic membership cards and passwords, is quite common. However, magnetic cards can be lost, and passwords can easily be forgotten. Thus, other means of establishing the identity of an individual using biometric physical quantities such as fingerprints, retinal patterns, etc. as data for authentication (hereinafter, authentication data) have also been proposed.
The use of signatures, an individual physical quantity, in the endorsement process for electronic business documents for identification and approval is a natural continuation of the signatures use on paper documents. In recent years the use of computer graphic systems in business has been growing, and signature data can be stored in the form of an image and can be pasted onto other computer data to indicate approval.
With the development of networks, it is now possible to provide a variety of services to a very large number of users on a network. The internet, for example, provides a wide spectrum of multimedia services, such as the WWW (World Wide Web). In some cases, as with services in banking, etc., access to these network services is granted only to individuals with proper identification, and therefore authentication is also an extremely important issue in providing network services.
However, for authentication of the identities of individuals on a network, use of the above-mentioned biometric authentication data is generally extremely difficult. For example, it would be necessary to install devices to read retinal patterns, fingerprints or palmprints at each and every terminal, and a system for relaying the data for such physical quantities over the network would have to be devised.
As a result, attention is focusing on the use of signature data as an individual physical quantity that can be used for verification on networks. Signature data has some advantages. For example, a signature can be easily input using a so-called tablet. The data may include not only the two-dimensional image data, but also changes in stylus pressure as well as the writing speed in order to establish the identity of the individual. A further characteristic is that tablets are available at a reasonable price, so that the cost of terminals can be kept low.
Recently, the biometric authentication data and signature data described above are being used in some networks as a means of authentication.
However, at the same time, the size of networks is increasing, the types of application servers providing services is increasing, and the number of clients receiving such services is reaching an extremely large scale. In particular, in networks like the Internet which is on a worldwide scale, there are many cases where the application server and the clients receiving its services are separated by extremely large distances. In such cases, the increase in traffic on the network resulting from exchanges of these more complex authentication data can be a large problem.